This is not a legend.
I had this happen on a V3R3 box in the 1990's.
From the 1-800 System Support phone number, you will be directed to Marketing to ensure that the machine has not been "pilfered and sent to a third world country". (That is what I heard being the reason for this check.)
date: Mon, 16 Jun 2014 10:01:59 -0400
subject: Re: V5R4 licenses
Could this be something different than a license key issue? Could this be
more of a "this machine has been powered off so long that you have to put
on a service password" kind of thing? I've not seen that but I've heard